1. Field of the Invention
The present invention relates to an apparatus for dyeing elongate textile materials under high pressure at high temperature, the textile materials being wound on a perforated cylindrical beam, and more particularly to such apparatus suitable for the dyeing treatment at low liquor ratio.
2. Description of the Prior Art
There are known a variety of dyeing apparatus for forcing dyeing liquid into and through elongate textile materials, such as yarns, tapes and fabrics, under high pressure at high temperature as the textile materials is wound on a rotating perforated cylindrical tube commonly known as "beam". The beam is supported concentrically within a cylindrical vessel. The dyeing liquid is forced, under high pressure and at high temperature, to penetrate layers of the textile materials radially outwardly from the inside of the beam on which the textile materials are wound. Difficulty has been experienced with many of the conventional apparatus in securing uniformity of dyeing treatment in all portions of the materials often resulting in different shades or hues both radially and axially of the roll of materials.
To eliminate this treatment defects, an improved apparatus has been proposed in Japanese Patent Post-Examination Publication No. 58-5301, Japanese Patent Post-Examination Publication No. 60-39786 and Japanese Utility Model Post-Examination Publication No. 59-9034, for example. In the prior apparatus, the dyeing liquid surface under which a lower portion of the roll of the materials is soaked is maintained so that the occurrence of different shades and hues due to the non-uniform amount of the dyeing liquid passing through the layers of the materials via the peirpheral holes of the beam, can be prevented.
However, in the case where the amount of textile materials wound on the beam is reduced, namely, the diameter of the roll of the materials is reduced, it is necessary to increase the amount of dyeing liquid, thus causing a remarkable change of the low liquor ratio. Consequently, dyeing conditions, compositions of the dyeing liquid for example, must be adjusted, which is scrupulous. Yet this scrupulous adjustment could not recover the low liquor ratio.
Further, if the dyeing liquid level in the treatment vessel is lowered, a large portion of the layers of the textile materials wound on the beam is necessarily exposed to air in the vessel. Partly because of this large exposed portion of the textile materials to air, and partly because of the non-uniformity of the amount of the dyeing liquid penetrating the materials from the inside thereof, the textile materials can be insufficiently wetted locally. Even though the textile materials is soaked at the lower portion of the beam, non-uniform dyeing is inevitable.
In addition, partly because a small amount of dyeing liquid is jetted out along the inner surfaces of opposite side rims of the beam and is struck thereagainst to scatter, and partly because bubbles are developed on the liquid surface due to the surface active agent as an additive, the dyeing liquid is attached to the wall surface of the vessel which wall surface is exposed to air, so that dyes and assistants contained in the liquid become cohered. Also, the low-molecular-weight materials eluted from the textile materials containing synthetic resin and synthetic fibers are attached to the wall surface of the vessel to become cohered. This cohesion of the dyes and assistants as well as the low-molecular-weight materials makes the wall surface of the vessel dirty. Further, these cohered materials easily fall on the textile materials to stick thereto, thus impairing the dyeing of the textile materials.